A comparison of two distributed systems: Amoeba and Sprite

Lecture Notes in Computer Science, 1990

Centre for Mathematics and Computer Science Amsterdam AMOEBA is a research project to build a true distributed operating system using the object model. Under the COST11-ter MANDIS project this work was extended to cover wide-area networks. Besides describing the system, this paper discusses the successive versions in the implementation of its model, and why the changes were made. Its purpose is to prevent ourselves and others from making the same mistakes again, and to illustrate how a distributed operating system grows in sophistication and size. I. Why This Paper "Those who learn nothing fi'om history are doomed to repeat it"-Santayana For about eight years now, we have been doing research on distributed operating systems, not only behind our desks, but also behind our terminals. The distributed system we are developing is called AMOEBA[l], and it is constantly evolving. It is being developed at the Vrije Universiteit and the Centre for Mathematics and Computer Science (CWI), both in Amsterdam. AMOEBA currently runs on Motorola 68020, National Semiconductor 32032, and MicroVax II processors. Both Ethemet and the Pronet token ring are supported by AMOEBA, and can be connected by a bridge. COST11-ter MANDIS is an international project investigating the management requirements for large international networks of computers. It has adopted the object-model as a framework within which to discuss the management of wide-area distributed systems. To experiment with this, the MANDIS project adopted the Amoeba distributed operating system, extended with a gateway for wide-area communication. Amoeba systems in Holland (Vrije Universiteit, CWI), the U.K. (Harwell Laboratories, Haffield Polytechnic), in Berlin (GMD/FOKUS) and in Norway (University of Troms0) have been connected into a single, transparent distributed system.

ACM SIGOPS Operating Systems Review, 1981

As hardware prices continue to drop rapidly, building large computer systems by interconnecting substantial numbers of microcomputers becomes increasingly attractive. Many techniques for interconnecting the hardware, such as Ethernet [Metcalfe and Boggs, 1976], ring nets [Farber and Larson, 1972], packet switching, and shared memory are well understood, but the corresponding software techniques are poorly understood. The design of general purpose distributed operating systems is one of the key research issues for the 1980s.

Computer Communications, 1991

As the price of CPU chips continues to fall rapidly, it will soon be economically feasible to build computer systems containing a large number of processors. The question of how this computing power should be organized, and what kind of operating system is appropriate then arises. Our research during the past decade has focused on these issues and led to the design of a distributed operating system, called Amoeba, that is intended for systems with large numbers of computers. In this paper we describe Amoeba, its philosophy, its design, its applications, and some experience with it.

Unlike many other operating systems, Amoeba is a distributed operating system that provides group communication (i.e., one-to-many communication). We will discuss design issues for group communication, Amoeba's group system calls, and the protocols to implement group communication. To demonstrate that group communication is a useful abstraction, we will describe a design and implementation of a fault-tolerant directory service. We discuss two versions of the directory service: one with Non-Volatile RAM (NVRAM) and one without NVRAM. We will give performance figures for both implementations.

1986

As distributed computing becomes more widespread, both in high-energy physics and in other applications, centralized operating systems will gradually give way to distributed ones. In this paper we discuss some current research on five issues that are central to the design of distributed operating systems: communications primitives, naming and protection, resource management, fault tolerance, and system services. For each of these issues, some principles, examples, and other considerations will be given.

Computer, 1991

udging from the enormous amount of distributed-system research carried out over the past decade, information processing experts have come t o recognize the advantages these systems possess. These research activ-J ities have led to the availability of more than 50 network and distributed systems. However, most of these systems can only partially succeed in attaining the major goals of a distributed system, which include transparency, higher performance, higher reliability and availability, and higher scalability. Of course, attaining all these goals in the first attempt is impossible. Nonetheless, gradual improvements are possible by learning from existing systems and trying to overcome their limitations. The University of Tokyo's Galaxy research project attempts to design, implement, and use a distributed computing environment based on this idea. Design goals and novel aspects Analyzing why existing In designing Galaxy, our primary goal was to build a distributed operating system suitable for use in both local and widearea network workstations. T o achieve this goal, we eliminated the use of broadcast protocols in any of our mechanisms, avoided the use of global-locking o r time-stamp-ordering mechanisms while maintaining the consistency of replicated information, and decentral-distributed systems are limited, the Galaxy research project borrows many concepts and proposed facilities ized the management of all globally useful information. novel system features that helped us achieve this goal include O u r second major goal was to ensure high performance. Design decisions and and integrates them developing the Galaxy kernel from scratch, rather than modifying a n existing using multiple-level interprocess communication mechanisms to meet the with its own novel Unix kernel; design features.

Proceedings of the 3rd workshop on ACM SIGOPS European workshop Autonomy or interdependence in distributed systems? - EW 3, 1988

IEEE Transactions on Software Engineering, 1989

This paper presents a retrospective view of the Charlotte distributed operating system, a testbed for developing techniques and tools to solve computation-intensive problems with large-grain parallelism. The final version of Charlotte runs on the Crystal multicomputer, a collection of VAX-111750 computers connected by a local-area network. The kernellprocess interface is unique in its support for symmetric, bidirectional communication paths (called links), and synchronous nonblocking communication.

Microprocessing and Microprogramming, 1988

A new generation of operating system was born during the last ten years: a distributed operating system oriented network. Three key-concepts are strongly developed: standardization, distribution and parallelism. One of these systems is CHORUS TM. This project launched at INRIA has elaborated an architecture for distributed systems. CHORUS is now being commercialized by the CHORUS systems company; it will be ported in the next few years on different machines, starting with the sPs7, PC/AT and SUN. CHORUS offers UNIX TM compatibility, is independent of the hardware architecture and of the network.

1979

Roscoe is an operating system implemented at the University of Wisconsin that allows a network of microcomputers to cooperate to provide a general-purpose computing facility. After presenting an overview of the structure of Roscoe, this paper reports on experience with Roscoe and presents several problems currently being investigated by the Roscoe project.